Football is more than a sport in Southlake, it is part of the identity, tradition, and pride of the community. In a city known for championship expectations and a culture built around excellence on the field, the work happening behind the scenes is just as important as Friday night lights. One of the key figures shaping that foundation is Doug Castleberry, Carroll ISD’s Strength and Conditioning Coach, whose role reaches far beyond lifting weights and conditioning drills. This position within Carroll Independent School District was created in 2023 and represents a shift in how student-athletes are developed across all sports, including the Southlake Dragons.
“The position takes the stress and liability of training off the coaches and allows them to worry about player skill development,” he said. “It allows me to plan our training curriculum year round and make sure our athletes are available, strong, conditioned and confident. Most importantly, it allows me to teach athletes how to properly train, when to push, when to dial it back, how to fuel their bodies, how to actively recover, and develop life skills and habits that lead to an active healthy lifestyle.” His work is woven into nearly every athletic program on campus, from Dragons football and volleyball to basketball, soccer, tennis, baseball, softball, swimming, water polo, wrestling, and both Dawson and Carroll Middle School athletics.
“Typically each group has different demands as every sport is different, but we keep things very simple and try to be brilliant at the basics before getting advanced,” he said. “I am an extension of the program and I will use as much time as the head coaches are willing to give me.” The training approach is built on structure, progression, and communication, beginning with pre activation preparation, movement work, and loading based on athlete readiness. “If we can’t body weight squat with great technique, I am not going to intensify that load with any weight,” he said. “With 12 programs and only one me, our coaches are a pivotal part in making sure the standard is upheld.”
The journey spans two decades in education. It began as an English teacher and football and baseball coach at Castleberry High School. From there, it moved to Northwest High School, where eight years were spent before transitioning fully into strength and conditioning. “I was an athlete my entire life, I love competition, and when the air was taken out of the ball for me, I wasn’t ready to let it go,” he said. “So I figured I could help kids develop and have more opportunities than I had.” Over the years, thousands of student-athletes, including the Dragons, have been coached and mentored.
When asked what is most enjoyable about the work, the answer points to athlete motivation. “The best part about working with athletes is they have something hanging over their head, playing time,” he said. “They are intrinsically motivated. The reward is when you see them compete and cash the check from all the training they put in.” Strength and conditioning coaches often operate in the background, but that role is embraced. “When you see them dig in and physically wear opponents down, that’s the reward.”
Beyond performance, the focus is long-term development. The goal is to prepare athletes for life beyond high school. “Be intentional about what we do and do hard stuff better than everybody else,” he said. “Life is hard, physically and emotionally, and if they haven’t dealt with that before the real world, they’ll crumble when adversity hits.” Some of the most meaningful moments come when former Dragons athletes share how prepared they felt entering college athletics. “Occasionally I will get messages from past athletes saying they are their college strength coach’s favorite and that they use me to demonstrate certain things because their technique is great,” he said. “That feels pretty good.” Pride also comes from championships, records, and team milestones.
What makes Southlake’s athletic culture stand out is the shared standard across the community. “Carroll is special because of the standards and expectations from our coaches and parents,” he said. “It truly takes a village.” Parents, teachers, and the broader community all help shape Dragon athletes into disciplined young adults. “We all have a hand in making sure the student athletes that walk out of Carroll are productive, hard working young people of integrity who know how to be part of something bigger than themselves,” he said.
For young athletes hoping to compete at the next level, the advice remains simple. “Train year round, not just during the off season,” he said. “Take nutrition seriously, eat better, and get your eight hours of sleep. You can’t out train bad nutrition and sleep deprivation.” After 20 years in education and athletics, motivation remains personal. “I am motivated by my family,” he said. “I want my wife and three boys to be proud of who I am.”
At the core of the philosophy is one belief. “Coaching is 100 percent about relationships,” he said. “X’s and O’s will only get you so far. If kids know you care, they’ll run through a wall for you.” In a city where football defines tradition and excellence defines expectation, this position continues to shape the unseen foundation that helps Dragon athletes rise to meet it.